不同贮藏温度对宰后猪里脊肉乳酸代谢通量的影响

Effects of Different Storage Temperatures on Lactic Acid Metabolism Flux in Postmortem Pork

为探讨不同温度处理对宰后猪里脊肉乳酸代谢通量的影响,本实验以猪里脊肉为材料,分别在4℃和-1℃下贮藏0.5、2、6、12、24、72、120、168 h,测定葡萄糖、乳酸和NADH含量的变化速率,并通过猪肉宰后僵直变化规律及乳酸代谢途径,建立中心代谢网络模型,进行乳酸代谢通量的分析。结果表明:在不同温度和贮藏时间下乳酸代谢通量均有明显差异,其中,-1℃贮藏时的葡萄糖进入磷酸戊糖途径的通量高于4℃,而在0.5~12 h贮藏期间-1℃贮藏时的乳酸代谢通量低于4℃,且在24~168 h贮藏期间-1℃贮藏时的乳酸代谢通量下降速率要慢于4℃。这表明贮藏温度越低分解代谢速率越慢,-1℃贮藏条件能够延缓乳酸的积累和下降速率,有利于鲜肉的保鲜。本研究从代谢的角度为鲜肉的保鲜提供了参考及理论依据。

We aimed to investigate the effect of different storage temperatures on lactic acid metabolism flux in postmortem pork loin in this study.Pork samples were stored at 4 or−1℃and evaluated for the rate of change in glucose,lactic acid and NADH contents at different time points(0.5,2,6,12,24,72,120 and 168 h).Besides,the pattern of rigor mortis and the lactic acid metabolic pathway were analyzed in order to a central metabolic network model to determine lactic acid metabolism flux.The results showed that lactic acid metabolism flux varied with storage temperature and time.The flux of glucose entering the pentose phosphate pathway at−1℃was significantly higher than at 4℃,while lactic acid metabolism flux between 0.5 and 12 h at−1℃was significantly lower than at 4℃.The rate of decline in lactic acid flux between 24 and 168 h at−1℃was lower than at 4℃.This indicated that the lower the temperature was,the slower the catabolic rate was.Storage at−1℃could delay the accumulation of lactic acid and the rate of glycolysis,which was beneficial to the preservation of fresh meat.This study provides a theoretical basis for fresh meat preservation from the perspective of metabolism.